There has previously been used a laminated piezoelectric actuator for driving a head of a hard disc drive, a head of a printer, and the like.
The number of internal electrodes in the laminated piezoelectric actuators have been on the increase, to obtain a larger amount of displacement. Further, a piezoelectric body layer between the internal electrodes is increasingly reduced in thickness for advancing miniaturization. In the case of reducing the thickness of a piezoelectric body layer between internal electrodes and increasing the number of internal electrode laminations, enhancing the conventional adhesion between the internal electrodes and the piezoelectric body layer has tended to be difficult even when the laminated piezoelectric body is crimped in a laminating direction before baking.
Therefore, Patent Document 1 proposes a laminated piezoelectric body manufacturing method described below.
As shown in FIGS. 13(a) to 13(f), first, a rectangular mother ceramic green sheet 101 is prepared in the manufacturing method described in Patent Document 1. A mother internal electrode pattern 102 is formed on the mother ceramic green sheet 101. The mother ceramic green sheet 101, on which the internal electrode pattern 102 is formed, and a mother ceramic green sheet 103, on the upper surface of which an internal electrode pattern 104 is formed displaced from the internal electrode pattern 102, are alternately laminated as shown in FIG. 13(b). One mother ceramic green sheet 101 and one mother ceramic green sheet 103 are alternately laminated in FIG. 13(b), but in practice, larger numbers of mother ceramic green sheets 101 and mother ceramic green sheets 103 are alternately laminated.
Moreover, a solid mother ceramic green sheet 105 is laminated. These mother ceramic green sheets 101, 103, 105 are laminated and pressed in a thickness direction, to obtain a first crimped body 106 shown in FIG. 13(c).
Next, the first crimped body 106 is cut in the thickness direction so as to have individual planar shapes of the laminated piezoelectric body. In such a manner, a chip 107 shown in FIG. 13(d) is obtained. The chip 107 has the same planar shape as that of the laminated piezoelectric body to be ultimately manufactured, but the number of internal electrode laminations is far smaller than the number of laminations of the ultimately manufactured laminated piezoelectric body. Hence, the internal electrodes 102, 104 and the piezoelectric body layers in chip 107 are tightly attached.
Thereafter, as shown in FIG. 13(e), a plurality of chips 107 are laminated in a laminating direction, followed by heating and pressing to obtain a laminated raw chip 108 shown in FIG. 13(f). At the time of obtaining the laminated raw chip 108, the number of plurality of chips 107 is selected such that the number of internal electrode laminations in the laminated raw chip 108 is the same as the number of internal electrode laminations in the laminated piezoelectric body to be ultimately manufactured.
The laminated raw chip 108 as thus obtained is heated to decompose binder, and then baked, so that a laminated piezoelectric body can be obtained. In the obtained laminated piezoelectric body, peeling between the internal electrodes and the piezoelectric body layers are hard to occur since the internal electrodes and the ceramic green sheets are tightly attached at the stage of the chips 107.    Patent Document 1: Japanese Unexamined Patent Publication No. 2002-314161